Boiler with variously-shaped heat exchange elements

ABSTRACT

There is described a boiler ( 1 ) including a burner ( 3 ), a heat exchanger ( 50 ) adapted to raise the temperature of a working fluid through heat exchange with an exchange fluid, including a plurality of heat exchanger modules ( 2 ) placed side by side in order to define a combustion chamber within which the burner ( 3 ) for the generation of exchange fluid is inserted, exchange walls ( 2 C) for the passage of exchange fluid, an expulsion chamber ( 2 D) for the exchange fluid fitted with a discharge flue ( 4 ) and a substantially parallelepiped casing ( 5 ) adapted to be filled with working fluid. The boiler includes side walls ( 5 D) inter-connected by stay-plates ( 6 ) placed between the heat exchanger modules ( 2 ) and top and bottom walls ( 5 B) and end walls ( 5 C) fitted with reinforcing elements ( 8 ) which prevent their deformation due to the pressure of working fluid.

The present invention relates to a boiler with variously-shaped heatexchange elements.

A heat exchanger is a device for changing the temperature of a fluid(“working fluid”) by forcing a heat exchange with another fluid(“exchange fluid”) a large amount of which is available at a temperaturesufficient to bring the working fluid to the required temperature. Whenthe heat exchange is over, the working fluid reaches the requiredtemperature, whereas the exchange fluid, which is spent and can nolonger sustain the heat exchange, is expelled.

A boiler comprises a heat exchanger fitted with a burner that cangenerate the exchange fluid (combustion fumes and hot air) within acombustion chamber, in order to heat water or air (the working fluid)within the boiler casing or body.

International Patent Application no. PCT/EP2006/067252 discloses amodular heat exchanger, consisting of exchanger modules, each of whichincludes:

a combustion chamber for the generation of an exchange fluid;

an exchange wall for the passage of the exchange fluid;

an exchange fluid ejection chamber fitted with a discharge flue.

Each of these exchanger modules is formed by a pair of basic elements,which are reciprocally connected in a facing position so as to form asingle block.

Once this heat exchanger is fitted inside a casing to form a boiler, itmay happen that the internal pressure is such as to cause thedeformation of the internal walls of the casing.

The object of the present invention is to obtain a boiler that canwithstand higher pressures than a traditional heat exchanger.

According to the invention, such an object is achieved by a boilerincluding a burner, a heat exchanger adapted to raise the temperature ofa working fluid through heat exchange with an exchange fluid, includinga plurality of heat exchanger modules placed side by side in order todefine a combustion chamber within which said burner for the generationof said exchange fluid is inserted, exchange walls for the passage ofsaid exchange fluid, an ejection chamber for said exchange fluid fittedwith a discharge flue, and a substantially parallelepiped casing adaptedto be filled with working fluid, characterised in that said casing hasside walls inter-connected by stay-plates placed between said heatexchanger modules, and top and bottom walls and end walls fitted withreinforcing elements to prevent their deformation due to the pressure ofsaid working fluid.

The heat exchanger could be of the same type described in PatentApplication PCT/EP2006/067252. The reinforcing elements may be rodsapplied externally to the walls of the casing. The stay-platesconnecting the side walls of the casing may have an area considerablysmaller than that of the casing walls, so as not to block the passage ofworking fluid inside the casing.

These and other features of the present invention will become moreapparent from the following detailed description of an embodimentthereof, which is disclosed by no way of limitation in the accompanyingdrawings, in which:

FIG. 1 shows a perspective view of a boiler according to the invention;

FIG. 2 shows a plan view of the boiler in FIG. 1;

FIG. 3 shows a side view of the boiler in FIG. 1;

FIG. 4 shows a section view along line IV-IV of FIG. 2;

FIG. 5 shows a section view along line V-V of FIG. 3;

FIG. 6 shows a simplified side view only of the heat exchanger;

FIG. 7 shows a front view only of the heat exchanger;

FIG. 8 shows a section view along line VIII-VIII in FIG. 6.

A boiler 1 according to the present invention is shown in FIGS. 1-5. Itcan raise the temperature of water or another working fluid through heatexchange with hot air and fumes, which constitute the exchange fluid.

The boiler 1 includes a heat exchanger 50 formed by eight exchangermodules 2 adapted to form a combustion chamber 2B, slotted exchangewalls 2C and an ejection chamber 2D. A burner 3, shown diagrammaticallyin FIGS. 1-5, is applied to the combustion chamber 2B at the inlet 51 ofthe first of the eight heat exchangers 2, while a discharge flue 4 isconnected to the outlet 52 of the ejection chamber 2D. The exchangefluid, generated inside the combustion chamber 2B, passes through theexchange walls 2C and then to the expulsion chamber 2D and the dischargeflue 4.

In order to be supported, the modules are built in a substantiallyparallelepipedal air-tight casing 5, shown in FIGS. 1-5. Such a casing 5is formed by the following walls:

a top and bottom wall 5B, parallel to the flow of exchange fluid insidethe discharge flue 4;

two end walls 5C (one at the front and one at the rear), parallel to theexchange walls 2C;

two side walls 5D, at right angles to the exchange walls 2C.

The casing 5 contains the working fluid that exchanges heat with theexchange fluid through the exchange walls 2C. Such a working fluid isintroduced through a conduit 7B and is ejected through another conduit7C; both conduits 7B and 7C are incorporated into the front wall 5C,which also includes the inlet 51, the support means for burner 3 and theoutlet 52 leading to the discharge flue 4.

Three stay-plates or panels 6 structurally connect the side walls 5D,and are positioned so as to be parallel to the exchange walls 2C and thefront walls 5C; such panels 6 have welded ends 10, so that they can besecurely inserted within cavities 11 between the side walls 5D (in otherembodiments, other means of attachment may be used, provided that theyare adapted to integrally join the panels 6 to the side walls). In thepresent embodiment, such cavities 11 appear as slots in the metal sheetthat forms the side walls 5D.

The size of panel 6 is such that its height is considerably shorter thanthe height of the exchange walls 2C, so as not to block the passage ofworking fluid.

The action of the panels 6 is to reciprocally hold the two side walls 5Din place, preventing them from deforming, even when the pressure of theexchange fluid increases to 4.5 bar.

The reinforcement rods 8 are applied to the front and rear walls 5C andto the top and bottom walls 5B, which structurally reinforce the casing5, preventing the walls from deforming under high pressures.

1. A boiler (1) including a burner (3), a heat exchanger (50) adapted toraise the temperature of a working fluid through heat exchange with anexchange fluid, including a plurality of heat exchanger modules (2)placed side by side to define a combustion chamber, within which saidburner (3) for the generation of said exchange fluid is inserted,exchange walls (2C) for the passage of said exchange fluid, an ejectionchamber (2D) for said exchange fluid fitted with a discharge flue (4)and a substantially parallelepipedal casing (5) adapted be filled withworking fluid, characterised in that said casing (5) has side walls (5D)inter-connected by stay-plates (6) placed between said heat exchangermodules (2), and top and bottom walls (5B) and end walls (5C) fittedwith reinforcing elements (8) adapted to prevent their deformation dueto the pressure of said working fluid.
 2. A boiler according to claim 1,characterised in that said stay-plates (6) are formed by panels (6) withends (10) securely fitted within cavities (11) between said side walls(5D) of the casing (5).
 3. A boiler according to claim 2, characterisedin that said panels (6) are parallel to said exchange walls (2C).
 4. Aboiler according to claim 3, characterised in that said panels (6) aresubstantially rectangular and of a height considerably shorter than theheight of said exchange walls (2C).
 5. A boiler according to claim 1,characterised in that said reinforcing elements (8) include rods appliedto said top and bottom walls (5B) and end walls (5C).
 6. A boileraccording to claim 5, characterised in that said rods (8) are on theoutside of said casing (5).
 7. A boiler according to claim 2,characterised in that said reinforcing elements (8) include rods appliedto said top and bottom walls (5B) and end walls (5C).
 8. A boileraccording to claim 3, characterised in that said reinforcing elements(8) include rods applied to said top and bottom walls (5B) and end walls(5C).
 9. A boiler according to claim 4, characterised in that saidreinforcing elements (8) include rods applied to said top and bottomwalls (5B) and end walls (5C).
 10. A boiler according to claim 7,characterised in that said rods (8) are on the outside of said casing(5).
 11. A boiler according to claim 8, characterised in that said rods(8) are on the outside of said casing (5).
 12. A boiler according toclaim 9, characterised in that said rods (8) are on the outside of saidcasing (5).